Spark-ignition device for explosive-engines.



PATENTED SEPT. 5, 1905- T. B. RENNELL. SPARK IGNITION DEVICE FOR EXPLOSIVE ENGINES.

APPLICATION FILED DEC.30,1903.

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No. 798,702. PATENTED SEPT. 5, 1905. T. B. RENNELL.

SPARK IGNITION DEVICE FOR EXPLOSIVE ENGINES.

' APPLICATION FILED DBO. 30,1903.

5 SHEETS-SHEET 2 No. 798,702. PATENTEI) SEPT. 5, 1905. T. B. RENNELL. SPARK IGNITION DEVICE FOR EXPLOSIVE ENGINES.

APPLICATION FILED DEG.80,1903.

5 SHEETSSHEBT 3 II N u. a M J /J m pnw a. 'mmm c0 womumoommzns. WASHINGTON o a PATENTED SEPT. 5, 1905.

T. B. RBNNBLL. SPARK IGNITION DEVICE FOR EXPLOSIVE ENGINES.

APPLICATION FILED DBO. 30,1903.

5 SHEETS-SHEET 4.

,iiiiiiiii'tW/m montw, u GIAMI m, wom-umocmwms. wnsnmmo u c N0- 798,702. PATENTED SEPT. 5, 1905. T. B. RENNELL. SPARK IGNITION DEVICE FOR BXPLOSIVE ENGINES.

APPLICATION FILED DEG. 30,1903.

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THORNTON B. RENNELL, OF DENVER, COLORADO.

SPARK-IGNITION DEVICE FOR EXPLOSlVE-ENGINES.

Specification of Letters Patent.

Patented Sept. 5, 1905.

Application filed December 80,1903. Serial No. 187,113.

To all whom it may concern:

Be it known that 1, THORNTON B. RENN ELL, a citizen of the United States, residing at Denver, in the county of Denver and State of Oolorado, have invented certain new and useful Improvements in Spark-Ignition Devices for Explosive-Engines, of which the following is a specification.

My invention has relation to that class of electrical igniting devices for gasolene or other explosive engines wherein a spark or series of sparks is caused to pass between terminals located in the explosion-chamber of said engine, said terminals being connected with the secondary coils of an induction-coil, in which a current is induced by the making and breaking of the circuit in the primary coils of the induction-coil, the device for making and breaking the primary circuit being controlled by the engine, and in such connection my invention has particular relation to the device for making and breaking the primary circuit.

The principal object of my invention is to provide a device for making and breaking the circuit in the primary coils of an inductioncoil at the proper time to induce a current of high potential in the secondary coils of the induction-coil to cause a spark or series of sparks to jump across the space between terminals connected with the secondary coils and located within a combustion or explosion chamber of an explosive-engine, which device shall be simple, durable, and eflicient in its action to insure at all times a proper ignition of the charge contained within the explosion-chamber of the engine.

The nature and scope of my invention will be more fully understood from the following description, taken in connection with the accompanying drawings, forming part hereof, in which Figure 1 is a diagrammatic view of an explosive-engine and an induction-coil with the device of my invention connected therewith. Fig. 2 is aview, partly in elevation and partly in section, of the upper end of an inductioncoil with the device for making and breaking the primary circuit attached thereto. Fig. 3 is a top or plan view of Fig. 2. Fig. 4 is a detail view of a section taken on the line {0 (I;

of Fig. 2. Fig. 5 is an end elevational view of the cam for controlling the device for makmg and breaking the primary circuit. Fig.

6 is a side elevational view of the cam shown in Fig. 5. Fig. 7 is a view, similar to Fig. 5, of a modification of the controlling device. Fig. 8 is an underneath plan view, partly in section, of the device shown in Fig. 7. 9 is a diagrammatic view showing the application of the device shown in Figs. 7 and 8. Fig. 10 is a front elevational view of a portion of the device shown in Fig. 2 and illustrating a feature of my invention. Figs. 11 and 12 are detail sectional views of a portion of the device shown in Fig. 2and illustrating other features of my invention. Fig. 13 isa diagrammatic view similarto Fig. 1, showing the application of my invention to a multicylinder engine. Fig. let is a front elevational view of an induction-coil having arranged in connection therewith the device for making and breaking the primary circuit and certain other devices shown in diagram in Fig. 13, and Fig. 15 is a sectional view taken on the line 3 1/ of Fig. 14.

Referring now more particularly to Figs. 1 to 12 of the drawings, the engine A has projecting within its explosion-chamber a the terminals 7/ and of a spark-plug b of the ordinary construction. connected by the wire 1 to one end of the secondary coil 0' of an induction-coil c of the usual construction, while the terminal Z1 of the spark-plug is grounded on the framework of the engine and is thence connected by the wire 2 to the other end of the secondary coil of the induction-coil. There are usually provided in engines of this type cam-shafts for operating the valves at proper intervals, and as these shafts rotate at the proper speed the cam (Z for controlling the device for making and breaking the primary circuit can be arranged on one of these shafts a. One end of a flat spring f is secured to the framework of the engine, while the free end thereof bears against the cam (Z. This cam (Z is slidably arranged on the cam-shaft a by means of a key a and has its throw portion (Z extending longitudinally and helically along the cam, and, as illustrated in Fig. 6 of the drawings, this throw portion is wider at one end than at the other. This cam (Z is adapted, therefore, to be slid along the shaft (0 for the purpose of changing the time and duration of the flow of sparks between the terminals of the spark-plug. The means of shifting the The terminal I) is cam (Z along the shaft (4 is not shown, as the same does not constitute part of this invention and devices of this character are well known in the art. It can, however, be shifted either manually or automatically. To the free end of the springf is pivotally secured the end of a connecting-rod g, the other end of this red g being fastened to a crank g, carried by a shaft arranged adjacent to the end of the induction-coil 0. also carries a cam which directly controls the making and breaking of the primary circuit in a manner to be presently explained. A platespring/l, secured at one end, as at it, to the induction-coil c. carries at the other end an armature 7o adapted to be attracted by the core 0 of the induction-coil when said core is energized by the passage of a current through the primary coils c of the inductioncoil. On the upper side of the spring is provided the usual platinum contact 71, touching the platinum point of the screw it when the spring it is free to move. The cam g however, normally depresses the spring it so that the contact 7t" does not touch the screw it". Extending from the free end of the spring 7b is a spring 11, carrying at its outer end a metallic wire a". The spring J is fulcrumed at a point intermediate of its ends on a stop It will be apparent that when the armature b and spring A are depressed the outer end of the springe'will be raised. hen the outer end of the spring 2 is in its lowermost position, the wire 2", carried by the same, will dip in mercury b, contained in a cup This 0111) 7a, preferably of glass, has fused in its upper end a glass tube 71: extending some distance into the cup and serving as a guide for the wire 2'. The construction of this cup is such that a considerable variation from a vertical position, as illustrated in Fig. 11, is permissible without materially changing the point at which the wire will leave the mercury when said wire is operated. As illustrated in Fig. 12, the cup 71; may even be turned to a horizontal position without spilling any of the mercury from the cup, although in such position the sparkingdevice would be inoperative. A wire 70 fused in the lower end of the cup b, establishes an electrical connection with a binding-post Z2". The cup Z/ is carried by and surrounded by a casing m, which casing is provided, as illustrated in Fig. 10, with a window or opening m opposite the level of the mercury in the cup in, so that the operation of the wire within the cup may be readily seen.

The primary circuit, as illustrated in Fig. l, is as follows: One pole of a battery n or other suitable source of electrical energy is connected by the wire 3 to one end of the primary coil 0" of the induction-coil, whereas This shaft l the other pole of the battery is connected by the wire at to the spring h, where two paths are offered for the passage of the current, one by way of the screw l1. and wire 5 to binding-post 71;; The other path is from the spring 72 through spring 1' and wire 71, carried by said spring, to the mercury Z3, thence by wire 7:" to the binding-post 7:". Fromthe r binding-post Z! the current passes by the wire 6 to the other end of the primary coil o of the induction-coil c. The cam y will normally depress the armature ll and spring as shown in dotted lines in Fig. 4, thereby causing the contact l1. to be separated from the screw /1., as well as raising the end of the wire vi out of the mercury b, so that no cu 1' rent will pass through the primary coil. As the cam (Z rotates with the shaft (0' it will at intervals oscillate the cam through the spring f, connecting-rod g, crank g, and shaft g to cause the same to release the spring it and permit the wire 71 to dip into the mercury and the contact 71. to touch the screw 71/. A current will then be permitted to pass through the primary coil, which will energize the core 0 of the inductioncoil, thereby causing the springs 7t and 1. to vibrate, and an intermittent current will be sent through said primary coils, which will induce a current of high potential in the secondary coils and cause a series of sparks to jump between the terminals 6 and If of the spark-plug 7/. It has been found in practice that when platinum contacts only are used to make and break the primary circuit considerable sparking will take place, which will soon corrode the contacts and bring the engine to a stop. However, by using a mercury interrupter, as described, in addition to the usual platinum contacts, most of the current will pass through the mercury interrupter and the sparking at the contacts will be obviated. The platinum contacts are useful, however, as offering an alternative path in case of any trouble with the mercury interrupter, and the screw /1, will also serve to limit the upward movement of the armature if, so that the proper movement of the wire z is insured.

In Figs. 7, 8, and 9 thereis shown a modilication of the means for controlling the device for making and breaking the primary circuit. In this form the cam (Z is rigidly secured on the shaft (4, and any change desired in the time and duration of the flow of sparks between the terminals of the spark-plug is obtained by securing the fixed end of the spring f to the end of a lever f, mounted on the bearing of the shaft a and capable of being partly rotated about the shaft (0. The shifting of the lever f causes the spring 7" to occupy varying positions w1th respect to the cam (Z and also serves to ad ust the position of the cam g to the variations in position of the connecting-rod g and crank g, as clearly illustrated in full and dotted lines in Fig. 9.

For multicylinder engines my invention could be used by multiplying the device hereinbefore described, according to the number of cylinders desired. To avoid this multiplicity of devices, it is preferable to modify my invention, as shown in Figs. 13 to 15 of the drawings. In this form the arrangement of the primary circuit and the means of controlling the same are the same as hereinbefore described. Each of the cylinders is provided with a spark-plug 6, and one of the terminals of each of these spark-plugs is grounded on the engine and is thence connected by wire 2 to one end of the secondary coil, while the other terminal of each of these spark-plugs is connected by the wires 7, 8, 9, and 10 to the terminals 0 of a switch 1), controlled by the engine. This switch is for the purpose of connecting the proper spark-plug with the secondary coil of the induction-coil, as required, and comprises a shaft 1), driven by a chain p from the engine. The shaft 1) carries an arm 19 having at its outer end a pair of metallic brushes 1)" to establish an electrical connection between one of the terminals 0 and a correspondingly-arranged terminal 0*. All of the terminals 0' are connected by the wire 11 to the other end of the secondary coil of the induction-coil. If desired, an additional sparkgap 3 may be placed in each of the secondary circuits 7, 8, 9, and 10 for the purpose of showing whether or not current is flowing to each cylinder, and it is believed that these extra spark-gaps will give the secondary current the form of a static discharge.

Having thus described the nature and objects of my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In an ignition device for gas-engines, an ind uction-coil in the secondary circuit of which the sparking terminals are included, in combination with means for interrupting the primary circuit of said coil at a plurality of points simultaneously, means under the control of the core of the induction-coil and arranged to periodically actuate said circuit-interrupting means, and mechanism arranged to render said circuit-interrupting means normally inoperative and to thereby maintain the primary circuit open at all points.

2. In an ignition device for gas-engines, an induction-coil in the secondary circuit of which the sparking terminals are included, in combination with a means'for interrupting the primary circuit of said coil at two or more points simultaneously, said means periodically under the control of the core of the inductioncoil and mechanism controlled by an engine for normally rendering said primary-circuitinterrupting means inoperative and thereby maintaining said primary circuit open at both points, substantially as and for the purposes set forth.

3. In an ignition device for gas-engines, an ind uction-coil in the secondary circuit of which the sparking terminals are included, in combination with a spring for interrupting the primary circuit of said coil at two or more points simultaneously, said spring being periodically under the control of the core of the induction-coil and mechanism controlled by an engine for'normally rendering said spring inoperative to maintain said primary circuit closed at both points.

4. In a device of the character described, the combination of an induction-coil, a spring carrying an armature, a screw adapted in conjunction with said spring to make and break the primary circuit, a cam adapted to normally depress said spring out of contact with said screw and means controlled by an engine for operating said cam, substantially as and for the purpose set forth.

5. In an ignition device for gas-engines, the combination of 'an induction-coil, a spring carrying an armature, an extension of said spring carrying a wire, a cup containing mercury into which said wire dips to close the primary circuit, a cam adapted to normally raise said wire out of the mercury and means controlled by an engine for operating said cam, substantially as and for the purpose set forth.

6. In an ignition device for gas-engines, the combination of an induction-coil, a spring carrying an armature, a screw adapted to contact with said spring, an extension of said spring carrying a wire, a cup containing mercury into which said wire dips, a cam adapted to depress said spring to normally hold said spring out of contact with said screw and to raise said wire out of the mercury, and means controlled by an engine for operating said cam, substantially as and for the purpose set forth.

7. In an ignition device for gas-engines, the combination of an induction-coil, a spring carrying an armature, a screw adapted to contact with said spring, an extension of said spring carrying a wire, a cup containing mercury into which said wire dips, a cam adapted to depress said spring to normally hold said spring out of contact with said screw and to raise said wire out of the mercury and a cam located on the cam-shaft of an engine adapted through intermediate mechanism to operate the cam controlling the contact-spring to allow said spring to close the primary circuit, substantially as and for the purpose set forth.

8. In an lgmition device for gas-engines,

having a series of explosion-chambers, a spark-plug for each of said chambers, an induction-coil, a spring for making and breaking the primary circuit of said induction-coil, means for controlling said spring by an engine, and means controlled by the engine for switching the secondary circuit of said induction-coil to each of said spark-plugs, substantially as and for the purpose set forth.

9. In an ignition device for gas-engines, an induction-coil having an armature-spring carrying a movable contact, a fixed contact, and a body movable about its own axis, to control said armature-spring, said body deriving its movement from the engine.

In testimony whereof I have hereunto set my signature in the presence of two subscribing Witnesses.

THORNTON B. RENNELL.

\Vitnesses:

E. O. CoRNIsH, MAMIE E. RYAN. 

